Digital micromirror device mounting system

ABSTRACT

A projection device is provided, wherein the projection device includes a digital micromirror device, a circuit board that further includes a first face and a second face, an integrated heat sink/stiffener; and a plurality of engagement mechanisms, wherein the plurality of engagement mechanisms is adapted to operatively couple the digital micromirror device to the first face of the circuit board and to secure the integrated heat sink/stiffener to the second face of the circuit board; and wherein the integrated heat sink/stiffener is adapted to provide structural support to the circuit board and to draw thermal energy away from the digital micromirror device.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of application Ser. No.10/860,375, filed Jun. 2, 2004, now U.S. Pat. No. 6,914,783 which claimsthe benefit of U.S. Provisional Application Ser. No. 60/475,367, filedJun. 2, 2003. Both applications are hereby incorporated by reference intheir entirety for all purposes.

TECHNICAL FIELD

The present disclosure relates generally to mounting systems for digitalmicromirror devices and other like components within an electricaldevice.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure is illustrated by way of example and not by way oflimitation in the figures of the accompanying drawings, in which thelike references indicate similar elements and in which:

FIG. 1 is a schematic illustration of an embodiment of a projectiondevice, including a digital micromirror device coupled to a circuitboard within the optical engine of the projection device.

FIG. 2 is an exploded view of an embodiment of a mounting system for adigital micromirror device, showing exemplary components of the mountingsystem.

FIG. 3 is an isometric view of the embodiment of FIG. 2, illustrating anexemplary configuration in which the components may be assembled.

FIG. 4 is an elevation view of the embodiment of FIG. 2.

FIG. 5 is a cross-sectional view of the embodiment of FIG. 2, takenalong the line 5—5 of FIG. 4.

FIG. 6 is a cross-sectional view of the embodiment of FIG. 2, takenalong the line 6—6 of FIG. 4.

FIG. 7 is a cross-sectional view similar to than of FIG. 6, illustratinganother embodiment of a digital micromirror device mounting system.

FIG. 8 is a cross-sectional view similar to than of FIG. 6, illustratinganother embodiment of a digital micromirror device mounting system.

DETAILED DESCRIPTION

A projection device 10 is illustrated schematically in FIG. 1.Projection device 10 may be a projector adapted to project an image ontoa display surface such as a screen, a wall, or other viewing surface orarea. Projection device 10 may be any suitable display device or imageprojector including, but not limited to, a digital projector, a liquidcrystal display (LCD) projector, a digital light processing projector,etc.

In some configurations, the projection device may include componentsdisposed generally within a casing 12, such as a light source 14 and anoptical engine (or light engine) 16. Light source 14 may be adapted toproduce a beam of light and project the light toward optical engine 16.

Light source 14 may include a lamp, such as a metal halide lamp or anultra-high-pressure (UHP) arc lamp, positioned within a reflector, whichmay be configured to direct most of the emitted light along apredetermined path. For example, light emitted from light source 14 maybe channeled through a spacer or interface tube 18, to the opticalengine. The emitted light may also pass through one or more filters,such as an infrared (IR) or ultraviolet (UV) filter, to filter outunwanted parts of the emission spectra of the lamp.

Optical engine 16 may include optical elements such as filters, lenses,mirrors, condensers, and the like. Optical engine 16 may also include animage-producing element 20 such as a digital micromirror device (DMD)22, which may be coupled to a circuit board 24. Although a DMD is shown,other embodiments may optionally include image-producing elements suchas an LCD panel or any other suitable image-producing element.Image-producing element 20 may be configured to project light toward oneor more mirrors or other optics, such as a projection lens 26, which inturn may be configured to direct light toward a display surface.

Projection device 10 may further include a power supply 28, which may belinked to components such as light source 14, image-producing element20, circuit board 24, and/or other components within the projectiondevice. Some projection devices may include more than one power supplydisposed throughout the casing.

In projection device 10, a mounting system may be used to operativelycouple circuit board 24 with DMD 22. Such a mounting system may alignthe components optically, electrically, and/or mechanically.

Overall performance of the projection device may be related to theaccuracy of the alignment. Thus, a mounting system may include one ormore engagement mechanisms, which may in turn apply compressive force tourge the various parts against each other. Optionally, a mounting systemmay include a stiffening member to provide structural support to thecircuit board, such as to prevent such compressive force from deformingthe circuit board.

Image-producing element 20 may output heat during use, and thus mayincrease the temperature of a projection device during use. If thetemperature of the device exceeds critical limits, portions of thedevice, such as a circuit board, may malfunction and/or have a shorterlife span. Maintaining temperatures within the device at operatinglevels thus may prevent the device from malfunctioning and/or increasethe lifespan of components and parts of the projection device. Thus, amounting system may also include a heat-dissipating member.

In a projection device having a compact design, a multi-functionalintegrated mounting system may be used to minimize the components usedto mount and maintain the DMD in a desired alignment. FIG. 2 illustratesan exploded view of such a DMD mounting system, indicated generally at30, which may include a heat sink/stiffener 32, a thermally and/orelectrically insulating layer 34, a circuit board 36, a spacer 38, and athermally conductive element, for example, a conductive polymer siliconepad 40, attached to a DMD 42 (which may be attached to its own circuitboard). A non-limiting example of suitable materials for thermallyconductive element 40, include silicone rubber or silicone. FIGS. 3 and4 illustrate views of DMD mounting system 30 in an assembledconfiguration.

Silicon pad 40 is shown as a square-shaped member with as front face 44,a back face 46 and a plurality of sides 48. Also, each of insulatinglayer 34, circuit board 36, and spacer 38 is illustrated to include anaperture (numbered 50, 52, 54, respectively) adapted to accommodatesilicon pad 40. Thus, as perhaps more clearly shown in FIG. 5, siliconpad 40 may be “sandwiched” between DMD 42 and heat sink/stiffener 32when DMD mounting system 30 is in an assembled configuration.Specifically, part of front face 44 of silicon pad 40 may be heldagainst heat sink/stiffener 32, and part of back face 46 may be heldagainst DMD 42. Thus, silicon pad 40 may conduct heat away from DMD 42towards heat sink/stiffener 32. Spacer 38 may also help to furtherinsulate DMD 42 while providing conductive pathways between circuitboard 36 and DMD 42.

Further, apertures 50, 52, 54 may be shaped such that sides 48 ofsilicon pad 40 may be prevented from contacting circuit board 36 whenDMD mounting system 30 is in an assembled configuration, which mayprevent conductive heat transfer from DMD 42 and/or silicon pad 40 tocircuit board 36.

Multiple functionalities may be integrated into individual components ofDMD mounting system 30. For example, in the depicted embodiment, heatsink/stiffener 32 is adapted both to stiffen circuit board 36 and tooperate as a heat sink. Thus, heat sink/stiffener 32 may be fabricatedfrom a rigid, thermally conductive material. Returning to FIG. 2, heatsink/stiffener 32 may include a first side 56 contoured similarly tocircuit board 36, such as to ensure a secure fit when held againstcircuit board 36. First side 44 may further be shaped to fit silicon pad40, for example to assure a secure mechanical interface, and/or toenable efficient heat transfer from silicon pad 40 to heatsink/stiffener 32. Heat sink/stiffener 32 may further include a secondside 46 including a plurality of formations 48 to enlarge to surfacearea of the second side to dissipate thermal energy. Formations 48 areshown as ridges, but other formations may be used.

Insulating layer 34 may be interposed between heat sink/stiffener 32 andcircuit board 36, and may consist of a thin layer of thermallyinsulating material. Insulating layer 34 may thus prevent thermal energytransferred to heat sink/stiffener 32 from passing to circuit board 36rather than dissipating from formations 48.

Insulating layer 34 is illustrated in FIG. 2 as a separate componentfrom heat sink/stiffener 32. In some embodiments, the insulating layermay be integrated with the heat sink/stiffener, which may furtherdecrease the profile of the DMD mounting system and decrease the numberof separate components used. For example, the area or areas of the firstside of the heat sink/stiffener adapted to contact the circuit board maybe treated with a thermally insulating material; the insulating layermay be fabricated and subsequently adhered to the heat sink/stiffener,and so forth.

Insulating layer 34, heat sink/stiffener 32, and other components of DMDmounting system 30 may be held in an assembled configuration by means ofa plurality of engagement mechanisms 62, shown in FIG. 2 to each includea mounting screw 64 and a compression spring 66. Engagement mechanisms62 may provide compressive force to electrically, mechanically, and/oroptically align the individual components of DMD mounting system 30.Specifically, mounting screws 64 may fit through compression springs 66and further through screw holes 68, 70, and 72, respectively disposed onheat sink/stiffener 32, insulating layer 34, and circuit board 36.

The configuration of engagement mechanisms 62 may be varied in order toapply a desired amount of compressive force to DMD mounting system 30.For example, various springs may be used to increase or decrease thecompressive force applied to the system. Additionally, tightening orloosening of screws 64 may adjust the amount of compressive force of themounting system. Thus, the use of the combination of multiple screws andsprings may enable adjustment and application of a desired compressiveforce.

As can also be seen in FIGS. 3 and 4, four engagement mechanisms 62 areshown in the four corners of heat sink/stiffener 32. Application ofcompressive force to the exterior perimeter of heat sink/stiffener 32and other components of DMD mounting system 30 may enable precisecontrol of the pressure exerted on the center of DMD 42. However, anynumber of engagement mechanisms and position for such engagementmechanisms may be used to provide an adequate compressive force.

FIG. 6 further illustrates an exemplary configuration of engagementmechanisms 62 with DMD mounting system, including mounting screw 64 anda compression spring 66. Compression of spring 66 may occur upontightening of screw 64. As illustrated, a portion of spring 66 maydirectly contact, or seat against, heat sink/stiffener 32. In otherembodiments, spring 66 may seat against insulating layer 34 (asillustrated in FIG. 7), and/or circuit board 36 (as illustrated in FIG.8). Moreover, in other embodiments, other types of engagement mechanismssuch as clips, latches, locks, and so forth, may be used.

Although the present exemplary embodiments illustrate the use of themounting system within a projection device, it should be appreciatedthat the mounting system described herein may be used in any suitableelectronic device incorporating a circuit board that must beelectrically and mechanically positioned relative to another component.For example, the mounting system may be used in electronic devices, suchas display monitors, etc.

Although the present disclosure includes specific embodiments, specificembodiments are not to be considered in a limiting sense, becausenumerous variations are possible. The subject matter of the presentdisclosure includes all novel and nonobvious combinations andsubcombinations of the various elements, features, functions, and/orproperties disclosed herein. The following claims particularly point outcertain combinations and subcombinations regarded as novel andnonobvious. These claims may refer to “an” element or “a first” elementor the equivalent thereof. Such claims should be understood to includeincorporation of one or more such elements, neither requiring norexcluding two or more such elements. Other combinations andsubcombinations of features, functions, elements, and/or properties maybe claimed through amendment of the present claims or throughpresentation of new claims in this or a related application. Suchclaims, whether broader, narrower, equal, or different in scope to theoriginal claims, also are regarded as included within the subject matterof the present disclosure.

1. A projection device, comprising: a digital micromirror device; acircuit board, including a first face and a second face; an integratedheat sink/stiffener; and a plurality of engagement mechanisms; whereinthe plurality of engagement mechanisms are adapted to operatively couplethe digital micomirror device to the first face of the circuit board andto secure the integrated heat sink/stiffener to the second face of thecircuit board; and wherein the integrated heat sink/stiffener is adaptedto provide structural support to the circuit board and to draw thermalenergy away from the digital micromirror device.
 2. A mounting systemfor use with a digital micromirror device, comprising: a circuit board;an integrated heat sink/stiffener adapted to provide structural supportto the circuit board, the integrated heat sink/stiffener including: afirst side contoured similarly to the circuit board; and a second sideincluding a plurality of formations to enlarge the surface area of thesecond side to dissipate thermal energy from the second side; and aplurality of engagement mechanisms; wherein the plurality of engagementmechanisms is adapted to secure the first side of the integrated heatsink/stiffener against the circuit board with a compressive force andcouple and align the circuit board with the digital micromirror device.3. The projection device of claim 1 wherein the integrated heatsink/stiffener further comprises ridges for dissipating thermal energy.4. The projection device of claim 1 wherein the plurality of engagementmechanisms comprise a mounting screw and a compression spring.
 5. Theprojection device of claim 4 wherein at least a portion of thecompression spring directly contacts the heat sink/stiffener.
 6. Theprojection device of claim 1 wherein the engagement mechanismsfacilitate at least one of electrical, mechanical, and optical alignmentof the circuit board to the digital micromirror device.
 7. Theprojection device of claim 1 wherein the integrated heat sink/stiffenerand the circuit board include alignable holes adapted to receive theplurality of engagement mechanisms.
 8. The projection device of claim 7wherein the alignable holes are disposed along the perimeter of at leastone of the integrated heat sink/stiffener and the circuit board.
 9. Theprojection device of claim 1 wherein the heat sink/stiffener comprisesrigid, thermally conductive material.
 10. The projection device of claim1 wherein the engagement mechanisms comprise at least one of clips,latches, and locks.
 11. The mounting system of claim 2 wherein theplurality of formations are ridges.
 12. The mounting system of claim 2wherein the plurality of engagement mechanisms comprise a mounting screwand a compression spring.
 13. The mounting system of claim 2 wherein atleast a portion of the compression spring directly contacts the heatsink/stiffener.
 14. The mounting system of claim 2 wherein theengagement mechanisms facilitate electrical alignment of the circuitboard to the digital micromirror device.
 15. The mounting system ofclaim 2 wherein the engagement mechanisms facilitate mechanicalalignment of the circuit board to the digital micromirror device. 16.The mounting system of claim 2 wherein the engagement mechanismsfacilitate optical alignment of the circuit board to the digitalmicromirror device.
 17. The mounting system of claim 2 wherein theintegrated heat sink/stiffener and the circuit board include alignableholes adapted to receive the plurality of engagement mechanisms.
 18. Themounting system of claim 15 wherein the alignable holes are disposedalong the perimeter of at least one of the integrated heatsink/stiffener and the circuit board.
 19. The mounting system of claim 2wherein the heat sink/stiffener comprises rigid, thermally conductivematerial.
 20. The mounting system of claim 2 wherein the engagementmechanisms comprise at least one of clips, latches, and locks.